1. Field of the Invention
This invention relates to a new physiologically active substance, Plipastatin, which exhibits an enzyme inhibiting activity against phospholipase A.sub.2, C and D and which will be useful as an immunosuppressive agent or as a type I anti-allergic agent.
2. Description of the Prior Art
Peptides having an acyl group are known and disclosed in, for example, Japanese Patent Unexamined-Publication (Kokai) No. 59-95252.
Adrenocortical steroids and cytotoxic immunosuppressors have been used as immunosuppressive agents. Also, anti-histaminics have been used as an anti-allergic agent.
All of the conventional immunosupressive agents have strong toxicity against hematopoietic organs in humans, so there has been a continuous need for the development of immunosuppressive agents having low toxicity. Since the human immune system is extremely complicated, immunosuppressive agents exhibiting new mechanisms of action are strongly desired. Also, the development of new drugs against type I allergic disorders is desired because there is no conventional drug that is capable of satisfactory inhibition of type I allergic reaction.